Horm Metab Res 2009; 41(5): 381-386
DOI: 10.1055/s-0028-1128140
Humans, Clinical

© Georg Thieme Verlag KG Stuttgart · New York

Effects of Acute Pinitol Supplementation on Plasma Pinitol Concentration, Whole Body Glucose Tolerance, and Activation of the Skeletal Muscle Insulin Receptor in Older Humans

A. J. Stull 1 [#] , K. V. Wood 2 , J. P. Thyfault 3 , W. W. Campbell 1
  • 1Department of Foods and Nutrition and Center on Aging and the Life Course, Purdue University, West Lafayette, IN, USA
  • 2Department of Chemistry, Purdue University, West Lafayette, IN, USA
  • 3Department of Nutritional Sciences and Internal Medicine and Harry S. Truman VA Hospital, University of Missouri, Columbia, MO, USA
Further Information

Publication History

received 08.07.2008

accepted 04.12.2008

Publication Date:
16 February 2009 (eFirst)

Abstract

Limited research with rodents and humans suggests that oral ingestion of pinitol (3-O-methyl-D-chiro-inositol) might positively influence glucose tolerance. This double-blinded, placebo-controlled, and cross-over study assessed the effects of acute pinitol supplementation on plasma pinitol concentration, glucose tolerance, insulin sensitivity, and activation of the skeletal muscle insulin receptor. Fifteen older, nondiabetic subjects (62±1 years, mean±SEM) completed four, 1-day trials. Subjects consumed a non-nutritive beverage with nothing (placebo) or 1 000 mg pinitol. Sixty minutes later, the subjects consumed beverages that were either energy- and carbohydrate-free (Sham) or contained 75 g glucose (OGTT). Blood samples were collected frequently over the 240-min testing period. For the OGTT trials only, vastus lateralis samples were obtained before the placebo and pinitol supplementation and 60 min after consuming the 75 g glucose beverage. Plasma pinitol concentration increased and was maintained for 240 min. Pinitol did not influence the fasting state and 180-min area under the curves for plasma glucose and insulin during the Sham and OGTT trials or hepatic (placebo 0.83±0.08; pinitol 0.80±0.08) and whole-body (placebo 6.10±0.54; pinitol 6.22±0.52) insulin sensitivities. Activation of the muscle insulin receptor was increased by 140% with glucose ingestion (Pre 0.62±0.12; Post 1.49±0.35), but pinitol did not influence this response. These results show that the pinitol supplement was quickly absorbed, but did not acutely influence indices of whole-body glucose tolerance and insulin sensitivity, or the activation of the skeletal muscle insulin receptor in older, nondiabetic humans.

References

1 During the time the research was conducted Dr. April J. Stull was a doctoral student and currently she is a postdoctoral fellow at Pennington Biomedical Research Center, Division of Nutrition and Chronic Disease and Botanicals Research Center, 6400 Perkins Rd., Baton Rouge, LA 70808, USA

Correspondence

W. W. Campbell, PhD 

Department of Foods and Nutrition

Purdue University

700 West State Street

West Lafayette

IN 47907-2059

USA

Phone: +1/765/494 82 36

Fax: +1/765/494 06 74

Email: campbellw@purdue.edu